html,body{
    height:100%;
    padding:0;
    margin:0;
}
div{
   box-sizing: border-box; 
}
.fz20{
    font-size: 20px;
}
/* flex */
.flex {
    display: flex;
    justify-content: space-between;
}
.flex-one{
    display: flex;
    flex-wrap: wrap;
}
.flex-two{
    display: flex;
    flex-wrap: wrap;
    align-items: center;
}